Super Sleezy issue with a private phone vendor

I recently bought two new phones from a private vendor. I bought sprint service with the phones. (this was not a sprint owned store)

When I bought the phones ( 1 Q, and 1 Razr) the manager told me the phones would be free. He told me that all I had to do was bring my first bill in to his store after I got it and he would do a manual price adjustment.
I brought my bill in to him on a monday and was told to return on thursday to pick up the adjusted bill.
I went in thursday to get my bill and was told that it wa being worked on and to come back around 4:00.
About a half hour later I get a call from a sprint representative apologizing for getting disconnected with me. The Rep tells me he just got disconnected with someone claiming to be me attempteing to get a credit to my account. Come to find out someone had attempted on three seperate occasions to get a credit to my account stating that they were me and that they felt they were over charged on the phone. The credit was denied on two of the three attempts. the credit was for the amount the vendor would have to pay to get me the phone for free and activation.
I went to the store and confronted the manager. He first said that he did not call impersinating me. when confronted with the fact that the spint Rep would have no reason to lie about getting disconnected with someone calling using my information the manager said that he was just trying to get the credit to my account quicker. I made a Police report about the incident and sprint is conducting an investigation.
I am posting this because i think this is probably happening quite a bit. if you got your phone from a private vendor who said they credited your account for your phone I would check out how the credit was obtained. Sprint keeps good notes on there customer issues (calls for credits)